//bat3.c  -- true RANDOM version for Unix/any ANSI C version
/********BATNUM -- BATtle of NUMbers, an old game ********/
/* by Wen-Nung Tsai */
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <time.h>
#define repeat do{
#define until(expr)  }while(! (expr))
#define then
/// ^^^^^^^^  意思是說以後 寫 then 等於沒寫
int myRand(int n) { return rand( ) % n; }
void randomize( ) { srand(time(0)); }  // make it TRUE random !
/// /// ++++++++++++++++++++++++++++++ /////////////
//////
typedef int bool;    // C 不認識 bool
 ///  ^^^^^^^^^^  意思是說以後寫  bool  相當於  int
typedef unsigned char byte;   //  意思是寫 byte == 寫 unsigned char
typedef char str40[41];    // str40  ==  char [41]; 可存 40 字
const
    char winMSG[][5] =  {"loss", "win "};
 int totalStone, maxTake;
 int c1, c2;   
 str40 tmpstr; /* used for gets */  //  char tmpstr[41];
 bool userFirst, userWin, lastToWin;   /* FLAGs */
void hello(void);
void prepareGame(void);
void askWhoFirst(void);
void computerTurn(void);
void userTurn(void);
/*****************************************************************/
void hello(void) {
     printf(" Welcome to play BATNUM --- BATtle of NUMbers,\n");
     printf("                 ---------- by tsaiwn@csie.nctu\n");
};
void prepareGame(void) {
     totalStone  =  myRand(20) + 11;   /* 11..30 */
     maxTake   =  3 + myRand(4);     /* 3..6 */
     lastToWin =  1;  // assume YES
     if( myRand(100) < 50) then lastToWin  =  0;
};
void askWhoFirst(void) {
     printf("Initially, we have ");    /* tell him the status */
     printf("%d",totalStone);
     printf(" stones.\n");
     printf("At least take 1. At most take %d.\n",maxTake);
     printf("The one who takes ");
     printf("last stone to %s.\n", winMSG[lastToWin]);
     printf(  "You want to go first(N,Y)? "); /* default is No */
     fgets(tmpstr, sizeof(tmpstr), stdin);
     c1 = tmpstr[0];
     userFirst = 0; if(toupper(c1)=='Y') then userFirst = 1;
     if(! userFirst) then printf("OK. I go first.\n");
};
void computerTurn(void) {
   int  meTake, tmp;
     tmp  =  totalStone;
     if(! lastToWin) then tmp =  tmp-1;   /* take last stone to loss */
     meTake =  tmp % (1+ maxTake);  /* try my best to WIN */
     if( meTake == 0) then meTake = 1;  /* seems that I will loss this game */
     totalStone  =  totalStone - meTake;
     printf("I take %d.\n",meTake);
     if( totalStone==0) then {   /* last stone took by computer */
	printf("I just took the last stone.\n");
	userWin =  1;  /* assume take last to loss */
	if(lastToWin) then userWin =  0; /* I won */
     } else {
	printf("There ");
	if(totalStone>1)then printf("are "); else printf("is ");
        printf("%d",totalStone);
        printf(" stone");
	if(totalStone>1)then printf("s");
	printf(" left.\n");
     };/*if totalSt..*/
}; // computerTurn
void userTurn(void) {
   long number; 
   char * endptr;
   int canTake, heTake; 
   bool askBefore;
     askBefore = 0;
     canTake = maxTake;  
     if(canTake > totalStone) then canTake  =  totalStone;
     repeat
	if(askBefore) then printf(" Error, ");
	printf("How many you take(1..%d)? ",canTake);
	fgets(tmpstr, sizeof(tmpstr), stdin); 
        askBefore =  1;
	number = strtol(tmpstr, &endptr, 10);  // atol(tmpstr);
	heTake = (int) number;
     until( (heTake >=1) && (heTake <= canTake) ); /*accept only legal move*/
     totalStone  =  totalStone - heTake;
}; // userTurn
void playGame(void) {
   if (! userFirst) then computerTurn();
   while( totalStone > 0)  {
      userTurn();
      if( totalStone==0) then { // gameOver, user took the LAST stone
	 printf("You just took the last stone.\n");
	 userWin =  0;  /* assume take last to Loss */
	 if(lastToWin) then userWin =  1;
         break;  // leave while Loop because gameOver
      };
      computerTurn();
   };  /* take turn until no more stone */
   /* no more stone, game over */
}; // playGame
int main(void) {    /* main */
   randomize();
   repeat
      hello();
      prepareGame();
      askWhoFirst();
      playGame();
      if( userWin) then printf("Congratulations! You Win!\n");
      else printf("Ar-Ha! I win!\n");  // computer won
      printf("Play more(Y,N)? ");
      fgets(tmpstr, sizeof(tmpstr), stdin);
      c1 = tmpstr[0];
   until( toupper(c1)== 'N');
   printf("Bye Bye!\n");
   return 0;
} // main